The choice of liaison service may affect the assumptions in which the proposed project is being reviewed and the improvements required for interconnection. The Energy Interconnection Service estimates that the proposed project will provide energy on the existing transmission network on an “available” basis. The network resource connection service roughly involves interconnection studies determining network upgrades to enable the transmission provider`s network to be provided with energy. Large central photovoltaic installations have a complex internal configuration and it is not possible or necessary to present each component as part of interconnection studies. The WECC guide recommends modeling large photovoltaic installations into machine equivalent. Quote from the WECC guide: “In this model, the equivalent generator represents the total production capacity of all inverters, the equivalent mounted pad transformer represents the total effect of all step-up transformers, and the equivalent collector branch represents the aggregate effect of the PV installation collector installation. With the right parameters of the model, this model should bring the load characteristics of the photovoltaic installations at the junction, the real and reactive collector system and the voltage profile at the “medium” inverter of the photovoltaic installation. An important observation is that the data requirements of the pro-forma LGIP and LGIA were intended for conventional generators. Another data set is required for photovoltaic installations.
Appendix A of the wecc guide contains an example of a demand for data on photovoltaic installations, which is more appropriate for the representation of the power flows of photovoltaic installations. It is recommended that this type of information be used to supplement the request for data in the pro forma LGIP. The facility study agreement is included in Schedule 4 of the LGIP and must be signed and returned to the transportation provider, with a higher value of $100,000 or a monthly estimate of the costs of carrying out the facility study. The purpose of the facility study is to specify and estimate the cost of the equipment, technology and construction work required to connect the proposed facility. The study will also identify electrical configurations of transformers, switching systems, meters and other station equipment. Finally, the study will also determine the nature and estimated costs of all transportation system upgrades required as a result of interconnection. Appendix A of Schedule 4 of the LGIP indicates the client`s choice for the completion of the facility study. Two options are available to the interconnection client regarding the accuracy of the facilities that must be provided in the facility study. Options are as follows: If a login request is made and concluded as “advanced” or completed by the transmission provider, the query is entered into the login queue.